two consecutive no's outof 1,2,3,...,n-1,n are removed. the average of remaining no's is 105/4.find n and the removed numbers
Let the removed numbers be and
Now
On solving we have two inequalities
Since and must be an integer.
Similarly solving the inequality, and thus
Therefore,
It is only for that p is an integer.Thus
Therefore the number of pages in the book are and the removed pages are and